（华东交通大学土木建筑学院， 南昌 330013）

［摘要］基于四点弯曲试验，研究了钢-聚丙烯腈混杂纤维(S-P混杂纤维)3种不同增强方式（局部增强、层布增强、全截面增强）对钢筋混凝土（RC）梁抗弯刚度的提高效果。结果表明：S-P混杂纤维局部增强方式与其他两种增强方式一样，可明显推迟导致试件破坏的横向垂直裂缝的出现和扩展，且也可使得其荷载-跨中挠度曲线具有明显的二次硬化特性，从而提高RC梁的抗弯刚度。但从经济性来看，仅将S-P混杂纤维用在RC梁高拉应力区的局部增强方式的效果最优。最后给出了S-P混杂纤维局部增强RC梁抗弯刚度的简化计算方法。

［关键词］RC梁； 钢-聚丙烯腈混杂纤维； 局部增强； 抗弯刚度； 计算方法

中图分类号：TU528文献标识码：A文章编号：1002-848X(2018)01-0054-04

Stiffness analysis of steel-polyacrylonitrile hybrid fibers partially-reinforced RC beams

Wang Kai, Ren Liang, Zhu En, Xu Linhua

(School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang 330013, China)

Abstract:Based on four point bending test, the improvement of  bending stiffness of reinforced concrete (RC) beams reinforced by steel-polyacrylonitrile hybrid fibers (S-P hybrid fibers) through partially-reinforced, layered-reinforced and total integrally-reinforced modes were investigated.The results show that S-P hybrid fibers partially-reinforced mode, like the other two reinforced modes, can obviously delay the appearance and expansion of transverse  cracks, and make the load-mid-span deflection curve have secondary hardening characteristics, resulting in improving the bending stiffness of RC beams. However from the economic point of view, the effect of S-P hybrid fibers partially-reinforced mode which is only used in the high tensile stress zone of RC beams is best. A simplified calculation method of the bending stiffness of S-P hybrid fibers partially-reinforced RC beam was proposed.

Keywords:RC beam; steel-polyacrylonitrile hybrid fiber; partially-reinforced; bending stiffness; computation method

*国家自然科学基金项目(51478183)，江西省青年科学家培养对象计划项目(20142BCB23012)，江西省高等学校科技落地计划项目(KJLD13039)。

作者简介：王凯，博士，副教授，Email:wklab@163.com。